The new 2007 security suites from Symantec and McAfee offer comprehensive protection against current security threats. The core antivirus, antispyware, and firewall protection in each package will keep your PC safe, and both suites offer secondary tools such as parental controls, privacy controls, and antispam features. For a multiple-PC setup, Symantec's suite is cheaper, and it offers better adware and spyware protection despite being marred by some performance holes.

Both Symantec and McAfee have done a good job redesigning their interfaces. Symantec's Norton Internet Security 2007 suite has a noticeably streamlined look, and it responds more quickly than in the past. An especially nice touch: Symantec decreased the level of bloat by making its secondary controls available as a freely downloadable (though hard-to-find) add-on pack at Symantec's site. McAfee's initial installation of Internet Security 2007 has those controls plus file backup, file-shredding, and junk-file-cleaning features, which some users may find valuable. Neither suite lets you use a master on/off switch to quit out of the software. The reason for this omission is to prevent users from inadvertently disabling their security protection; however, it also makes troubleshooting your PC difficult.

Symantec's installation recommended uninstalling competing stand-alone antispyware products, warning that other programs' real-time protection interferes with its own protection. I found this to be true when I ran both the Symantec program and Spybot-S&D, which should soon have a patch to alleviate the problem. But it's not clear whether simultaneously running another antispyware program will have the same compatibility problems as running another antivirus program, which we definitely do not recommend. This year Symantec includes three PC licenses with the $70 price for a year's worth of virus updates; that's a good deal. Be warned, however, that if you buy either company's suite online with a credit card, the company will automatically charge you for the next year's renewal if you don't opt out first.

In malware tests conducted by AV-Test.org, both suites performed well, though each had weaknesses. Symantec's suite detected only 74 percent of malware embedded in Microsoft Office Object Linking and Embedding (OLE) objects, whereas McAfee detected 100 percent. When scanning malware hidden in compressed files, Symantec's suite detected 75 percent of the interlopers while McAfee's detected 90 percent.

On the other hand, Symantec's protection against adware and spyware was exceptional. It detected 95 percent of adware and spyware samples, versus the McAfee suite's detection rate of only 74 percent. McAfee's suite incurred a significant 0.09 percent false positive rate; Symantec's suite incurred an acceptable 0.02 percent rate. (For more information on how the products were tested, see "How We Test," below.)

Both suites block you from visiting phishing Web sites, but McAfee's suite has a better antiphishing implementation. Symantec's version works with Internet Explorer only. An obtrusive bar beneath the Address Bar turns red if you stumble across a phishing site. McAfee's protection--which also works with Firefox--incorporates a blocked-site dialog box that appears as a Task Bar pop-up; the McAfee suite also employs the extremely useful SiteAdvisor plug-in to warn you about bad sites.

In my informal tests, both products' antiphishing protection was effective. Since each focuses on sites that collect financial or confidential information, neither product prevented me from going to a Web site that fraudulently uses the TrustE privacy seal to collect contact information only--so it's still important to be vigilant when surfing the Web.

Another usability issue: McAfee's parental controls can now analyze images for inappropriate content (such as nudity), but the feature is tempermental. For example, when opened on a PC where I was not the administrator, it enabled the "Teenagers and children" setting by default and on one occasion blocked me from viewing Yahoo's Web site; a few other times, at the Web site of a day spa, it blocked several images of women's faces. On another PC where I was the administrator, however, even though I had enabled the "Teenagers and children" setting, it allowed display of two topless images on Sex.com's home page. (It did successfully block the site's Featured Movie of the Day image.)

Your PC will take a performance hit for all this protection, too--a little more so with McAfee's suite. In speed tests conducted by AV-Test.org, copying 760MB of files on a test PC equipped with a 2.8-GHz Pentium 4 CPU, 512MB of RAM, and an 80GB hard drive (without any security protection enabled) took only 36 seconds. Copying with Symantec's real-time protection turned on took 80 seconds; and McAfee's suite with real-time protection turned on took 97 seconds to perform the same task.

Symantec's suite is the better security value, though McAfee offers more nonsecurity utility features, the impressive SiteAdvisor tool, and excellent antiphishing components.